In an air jet wearing loom, it is conventional to use, for picking or penetration of the weft yarn into the shed of warp yarns, an air guiding comb composed of a row of aligned air guiding teeth. The comb is formed with an air guiding passage, defined by apertures respectively formed in the teeth, through which the weft yarn passes during operation of the loom. Each of the teeth is formed to have a straight part and an arcuate part which are combined to form the aperture leaving an exit slot between the straight part and the leading end of the arcuate part. Recently, it has been proposed to provide such air guiding teeth with flat spring members which extend from the arcuate parts to substantially close the respective exit slots during penetration of the weft yarn into the air passage of the comb and to open the exit slots upon exit thereof therethrough. Actually, such a tooth equipped with the flat spring member has exhibited fairly good result in regard to reduction of losses of energy of the air stream passing through the air passage of the comb.
However, the air guiding tooth of this type has a serious drawback, which is that, upon penetration of the weft yarn into the air passage of the comb, a part of the pressurized air stream is caused to flow or leak through a clearance which is formed near the exit slot between the arcuate part and the flat spring member. This causes a leading end or edge of the travelling weft yarn to be conducted toward the clearance and finally entangled with the flat spring member and/or the arcuate part. This means the failure of the penetration of the weft yarn through the air passage of the guiding comb.